1. Field of the Invention
The present invention relates to a remote control transmitter for use in remote control operation mainly on various types of electronic equipment.
2. Background Art
In the recent promotion of enhancing the functionality of various types of electronic equipment, such as a television, video player, and air conditioner, a remote control transmitter capable of ensuring various kinds of operations is also required for remote-controlling such equipment.
A description is provided of such a conventional remote control transmitter, with reference to FIG. 7 and FIG. 8. FIG. 7 is a sectional view of a conventional remote control transmitter. With reference to FIG. 7, a plurality of operating bodies made of an insulating resin are placed in a plurality of open holes provided through the top face of box-shaped case 1 made of an insulating resin so that the operating bodies are vertically movable.
Pressure-sensitive conductive sheet (hereinafter simply referred to as “conductive sheet”) 3 includes conductive particles dispersed in a base material made of silicone rubber or the like. Wiring board 4 has wiring patterns (not shown) formed on the top and bottom faces thereof. Conductive sheet 3 is placed above the top face of wiring board 4. On the top face of wiring board 4, a pair of fixed contacts 5 made of copper, carbon, or the like are formed.
Spacer 6 made of an insulating resin is formed between conductive sheet 3 and wiring board 4 so as to surround a plurality of fixed contacts 5. The bottom face of conductive sheet 3 and fixed contacts 5 are opposed to each other so that a predetermined clearance is provided therebetween. Thus, a plurality of pressure-sensitive conductive contact parts (each hereinafter “contact part”) 7 are formed. Further formed on the bottom face of wiring board 4 are transmission part 8 made of a light emitting diode or the like, and control part 9 made of a microcomputer or the like and causing transmission of a remote control signal from transmission part 8 according to electrical connection in contact part 7 or resistance thereof. Cover 10 made of an insulating resin covers the bottom face of case 1.
While a program list or the like is displayed on the display screen of a liquid crystal device or the like of electronic equipment to be remote-controlled, the conventional remote control transmitter structured as above is directed to the electronic equipment, and one of operating bodies 2 is pressed with a finger. With this operation, the bottom face of this operating body 2 presses conductive sheet 3. Conductive sheet 3 flexes downwardly and makes contact with a corresponding pair of fixed contacts 5. The pair of fix contacts 5 is electrically connected via conductive sheet 3.
FIG. 8 is a chart showing a signal waveform supplied from the conventional remote control transmitter. With reference to FIG. 8, when one of operating bodies 2 is continuously held down with a constant force, operation signal A1 is transmitted from transmission part 8 to the remote control receiver periodically and repeatedly at intervals of 20 to 50 msec. Further, when another one of operating bodies 2 is pressed, the electrical connection in corresponding contact part 7 and changes in the resistance between corresponding fixed contacts 5 are detected by control part 9. A remote control signal corresponding to the pressing operation is transmitted from transmission part 8. In response to the transmitted remote control signal, the cursor displayed on the display screen of the electronic equipment moves in the downward or horizontal direction, for example.
In this manner, the conventional remote control transmitter is structured so that pressing a plurality of operating bodies 2 allows remote control of the moving direction, speed, or the like of the cursor displayed on the display screen of the electronic equipment.
Japanese Patent Unexamined Publication No. 2006-33680 is an example of the known information on the conventional techniques related to this invention.
However, the conventional remote control transmitter has the following problem. When one of operating bodies 2 is continuously held down with a constant force, the same operation signal A1 is periodically and repeatedly transmitted from transmitter 8 at predetermined intervals as shown in FIG. 8, although the moving direction and speed of cursor 33 on display screen 31 are unchanged. This operation causes continuous power supply from the battery stored in the remote control transmitter to transmission part 8 and control part 9, thus consuming the battery.